Q. I’ve been following the story of Rep. Vance McAllister, R-La., ever since he was caught kissing a staffer, and am wondering whether he could face ethics sanctions. I can think of instances in the past where similar conduct by a member has led to ethics investigations. But, in the stories I’ve seen about McAllister, the focus has always been on political fallout — not on whether he could face ethics charges. Did McAllister violate ethics rules by having an affair with a staffer? A. No House ethics rule explicitly forbids a member from adultery, even with a staffer. But, of course that doesn’t mean that such conduct is without risk. McAllister is experiencing firsthand the political consequences of being caught kissing a staffer on a videotape released last month. The Republican, who won his seat in a special election less than six months ago, has already announced that he will not seek re-election this fall. And several Republican leaders have urged McAllister to consider resigning.

Take former Sen. John Ensign, R-Nev., who had an affair with a longtime staffer. Before news of his affair became public, Ensign was alleged to have taken actions to cover it up, including arranging for his parents to make payments to his mistress’ family totaling $96,000. It was those actions and payments, not the adultery itself, that were at issue in investigations by the Senate Ethics Committee, the Federal Election Commission and the Department of Justice. Ensign ultimately resigned before the Ethics Committee completed its investigation.

But the committee published an investigation report anyway, concluding that there was credible evidence to conclude that Ensign had violated Senate rules and federal civil and criminal laws, and had engaged in improper conduct reflecting upon the Senate. The report took pains to make clear, however, that adultery alone was not the basis for any of the violations. "Whether a person is unfaithful to his or her spouse is generally the couple’s own business to deal with," the report said.

On the other hand, the fact that Ensign’s mistress was a staffer for the senator did play a role in the report’s conclusions as to some of the alleged violations. Given the power that Ensign had over his mistress and her husband (who Ensign also employed), and the effects the affair and its dissolution had upon them, the report concluded that there was “substantial credible evidence” that Ensign discriminated against his mistress on the basis of sex, and that her husband was also a victim of that discrimination.

This is not to say that for a member to commit adultery with a subordinate is to commit a per se ethics violation. To the contrary, adultery with a staffer has never been the sole basis for ethics sanctions against a member.

Nonetheless, the fact that McAllister employed the woman he was caught kissing could encourage his peers to request an ethics investigation. In May 2010, after Rep. Mark Souder admitted to having an affair with a staffer, a fellow House Republican from Indiana, Mike Pence (who is now governor) contacted the Ethics Committee about Souder. Speaker John A. Boehner, R-Ohio, then demanded that Souder resign, and wrote a letter to the Ethics Committee. Before the committee could take any action, Souder left office.

You might ask: If there is no rule explicitly forbidding a member from committing adultery with a staffer, on what basis could there be an ethics investigation? A fair question, but the answer is that the Ethics Committee has broad authority to investigate all potential ethics violations, and has an ace in the hole when it comes to conduct that is not specifically covered by an ethics rule. Rule 1 of the Code of Official Conduct, which is sort of a catch-all for bad behavior by members and staffers, states, “A Member, Delegate, Resident Commissioner, officer, or employee of the House shall behave at all times in a manner that shall reflect creditably on the House.”

In short, do something that might not reflect creditably on the House, and the committee might investigate.

C. Simon Davidson is a partner with the law firm McGuireWoods. Submit questions to cdavidson@mcguirewoods.com. Questions do not create an attorney-client relationship. Readers should not treat his column as legal advice.